The clip, the latest in a long line of alleged UFO sightings recorded by the ISS livestream, is said to show a huge cylindrical shaped object before it disappears from view.

But, it also appears to look transparent rather than solid.

It was found in NASA footage uploaded online by the space agency by persistent alien chaser, Scott C Waring, editor of ufosightingsdaily.com.

He is convinced it is an alien space craft actually captured on camera.

It appears to move slowly across the blackness of space, then it moves across the Earth’s skyline before eventually fading from the NASA camera.

Mr Waring said: “The UFO was partially cloaked, which made it look transparent.

“In the deep blackness of space, blending into the environment means you will be safer from other alien species that may not be so friendly.”

Mr Waring and other armchair UFO spotters have found scores of these translucent UFOs in the ISS footage over the past few years, and they claim there is a major cover up by NASA to deny their existence.

But, NASA, which will not comment on individual cases vehemently denies any cover up or any evidence of UFOs or aliens.

Experts from the space agency say that the transparent objects which appear on camera are relfected light from part of the ISS itself, or lens flares, when light refracts inside the lens and a stray piece of light is beamed onto the image from within.

Scott Brando runs the hoax-busting website ufoofinterest.org and is fed up with claims of lens flares and reflections being UFOs, as he says it damages genuine research.

He analysed the latest “cylinder UFO footage” and concluded it was just another lens flare.

He even produced a video showing the exact point at which the lensflare was created by sunlight hitting the camera.

He tweeted: “An alien cylinder spotted near ISS? No, it’s another lens flare visible from four different times at the same point.”